1. Field of the Invention
The techniques described herein relate to multi-layer film capacitors.
2. Discussion of the Related Art
Multi-layer film capacitors are known and have been used in applications such as filtering and power decoupling for integrated circuits. U.S. Pat. No. 5,745,335, entitled “Multi-Layer Film Capacitor Structures and Method” by Watt (hereinafter “Watt”) describes two different types of film capacitors. FIGS. 1-17 of Watt show a multi-layer film capacitor having a mesa structure, in which each upper layer is progressively smaller in area, and each upper layer fits within the perimeter of the lower layers. FIG. 18 of Watt shows a different multi-layer film capacitor having a staggered construction, in which some of the upper layers overhang the lower layers. Watt states that the staggered capacitor structure has several disadvantages compared to the mesa structure (Col. 12, lines 13-20). For example, in the staggered structure, the corners of the underlying films can cause problems when depositing films on top of them. Also, some areas may be too thick for suitable film adhesion. Additionally, the locations that can potentially be used for contact areas are more restricted. A further disadvantage is that the staggered structure can have increased parasitic capacitance problems. Thus, Watt states that the mesa structure is preferred over the staggered structure (Abstract).